This is the second renewal application of the Molecular Biophysics Training Grant at Washington University. The Molecular Biophysics Graduate Program is one of twelve Ph.D. Programs within the Division of Biology and Biomedical Sciences. Its focus on quantitative aspects of biological systems, and its requirement for significant math and physics backgrounds of its students make it unique at Washington University. The current Program Director, Dr. Kathleen Hall, has been responsible for the Program since 1997, and is expected to continue in this position for at least several more years. She is also P.I. on the Training Grant. She is assisted in administration of the Program by a steering committee of faculty and a Program coordinator in the Division office. The Program has been in place for eleven years, and has graduated twenty students with Ph.D. degrees. Our statistics show that the number of students who apply has remained relatively constant over the past five years, as has the number that matriculate. Currently, there are fifteen students in the Program, including two underrepresented minority students. There are 40 faculty members affiliated with the Program, four of whom are junior faculty. They come from seven Departments in the Medical School, and also from Biology, Chemistry, Physics, Biomedical Engineering, and the Danforth Plant Science Center. The Molecular Biophysics Graduate Program maintains a web site that lists faculty, current and past students, and events. The annual retreat, begun in 1994, joint with the Biochemistry and Bioorganic Chemistry graduate Programs, is documented on the web site. There are monthly Biophysical Evenings that showcase our faculty or introduce new developments in Biophysics; these began in 1992. Program activities are supported in part by the Division and by the Department of Biochemistry & Molecular Biophysics. There are five training positions funded by this Training Grant. Based on our admission and recruitment statistics, that number is appropriate for our Molecular Biophysics Program, and so with this renewal, we request five years of support at the level of five students per year.